Infectious Diseases in Critical Care Medicine

infiltrates.S. aureus(MSSA/CA-MRSA) CAP occurs only with influenza pneumonia and not

alone. The third clinical presentation of influenza A pneumonia is that of initial influenza

pneumonia followed by a period of improvement (*1 week), followed byS. pneumoniae or

H. influenzaepneumonia with new fevers and focal/segmental infiltrates on CXR. Patients

Table 11 Empiric Antibiotic Therapy of Severe CAPa

Severe CAP

Usual CAP pulmonary

pathogens Empiric antibiotic therapy

Normal hosts

CXR:focal/segmental infiltrates S. pneumoniae Respiratory quinolone

H. influenzae or

M. catarrhalis ceftriaxone

Atypical CAP

pathogens

plus either

doxycycline or azithromycin

Compromised hosts

CXR:focal/segmental infiltrates Respiratory quinolone

Disorders with;B-lymphocyte S. pneumoniae or

function/HI with mild/moderate H. influenzae ceftriaxone

hypoxemia A–a gradient<35) M. calarrhalis plus either

doxycycline or azithromycin

Disorders with;T-lymphocyte Legionella Respiratory quinolone

function/CMI with mild/moderate Q fever or

hypoxemia A–a gradient<35) doxycycline

CXR:diffuse bilateral symmetrical

infiltrates

Mild/moderate hypoxemia

(A–a gradient<35)

Severe hypoxemia

(A–a gradient>35) Human seasonal Influenzab

Avian influenza (H5N1)

Swine influenza (H1N1) Oseltamiviramantadine

Adenovirus

RSV

HPS

SARS

CMV Ganciclovir

PCP TMP–SMX or pentamidine or

atovaqone plus steroids

aTreat while r/o mimics of severe CAP.

bInfluenza pneumonia with focal segmental/lobar infiltrates treat for MSSA/CA-MRSA (see Table 12).

Abbreviations: TMP-SMX, trimethoprim-sulfamethoxazole; HPS, hantavirus pulmonary syndrome; SARS, severe

acute respiratory syndrome; CMV, cytomegalovirus;Pneumocystis (carinii) jiroveciipneumonia (PCP); RSV,

respiratory synctival virus.

Table 12 Severe CAP with Infiltrates and Cavitation

Rapid cavitation(<3 days)a
.S. aureusa(MSSA/CA-MRSAb)
Moderately rapid cavitation(3 to 5 days)
.K. pneumoniae
Slow cavitation(>5 days)
.Aspiration pneumonia (oral anaerobes)

aonly in patients with human seasonal influenza A pneumonia or an influenza-like illness (ILI).
bOnlyS. aureusandP. aeruginosacause rapid cavitation in<3 days.P. aeruginosais not a CAP pathogen except

with cystic fibrosis/chronic bronchiectasis.
Abbreviations: CAP: community-acquired pneumonia; MSSA, methicillin-susceptibleS. aureus; CA-MRSA,
community acquired methicillin-resistantS. aureus.

172 Cunha